TREE OF THE MONTH - MARCH 2017: THE HAZEL

Hazel nuts - once a vital food source, now often placed in a bowl before Christmas and thrown away afterwards. Image by Fir0002 CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons

Spring is stirring! The Witch Hazel flowers have faded; the snowdrops are still in full display, accentuating the dark red of a Hellebore here at Hearne HQ; daffodils have erupted through the lawn and the Magnolia flower buds have swelled and will burst open any day now. But in the countryside it is now the male catkins, or 'lamb's tails', of the Hazels that catch the eye on my walks with Badger, the 16 year old Springer Spaniel who hobbles rheumatically along with me - sadly a Springer without spring these days.

Hazel catkins sway in the breeze before the fallen Oak behind - Ashington, Dorset, 5 March 2017.

Hazels are in the Betulaceae family which also includes Birch, Alder and Hornbeam. The map below shows their native range, reaching Britain hot on the heels of Birch as one of the first trees to colonise our shores after the retreat of the last ice age - arriving at around 8500BC. Not surprisingly for a tree that has been around so long, they have played an important role in our history.

The common Hazel is native to Europe, western Asia and north Africa. Image by By Giovanni Caudullo, via Wikimedia Commons

Male catkins and female flowers appear on the same tree. The catkins develop in autumn and remain short, dark and cylindrical over winter. The anthers burst in February and the catkins turn yellow and elongate, hanging in clusters of two to five. The females are bud-like with only the minute red tips protruding at flowering time - though they can still give an attractive red 'haze' in sufficient numbers. Like its Betulaceae cousins, it is wind pollinated, but,  unlike the Birch, I have not heard that it bothers those that suffer from hay fever.

Female flower. Image by H. Zell (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) via Wikimedia Commons

Hazel thrives on a loamy soil and will do well in chalky areas. It tolerates some shade but doesn't thrive and barely flowers in it. As larger trees began to colonise the country and shade them out, they retreated to open areas likes cliffs and river banks; it was only with the clearance of woodland by early settlers that it returned in numbers.

Hazels can form small trees of around 6-10m in height but they will mostly be seen as multi-stemmed shrubs renewing from cut stumps (stools) - the cyclical management known as coppicing.

The Hazel is mostly associated with its abundance in our hedgerows and as coppice underwood. It is the ability of the tree to readily sprout from cut stumps (the regrowth being called 'spring'), and the extraordinary flexibility of its regrown poles that has led to its wood being extensively used despite its diminutive size. Deliberate 'coppicing' began around 4000 years ago; the poles can be split lengthways and twisted and bent back on themselves without breaking. From neolithic times the split canes, or wattle, has been used extensively. It made hurdles, fencing and laid the foundations for wattle-and-daub walls. It is also still used for pegging down thatch. Smaller scale use still includes pea and bean sicks and they are popular for decorative walking sticks - especially those that have been constricted by Old Man's Beard (Clematis vitalba).

Hazel coppice - Ashington Dorset.

Coppicing has enjoyed something of a revival and you will certainly find coppice craftsmen at country shows and fairs, selling anything from hurdles and walking sticks to rustic furniture and charcoal. Coppice workers report a diversity of workability of poles from different stools, particularly in the manner in which they split, to the extent that they can predict the behaviour by subtle differences in the appearance of the bark. The resurgence of coppicing has met with the approval of ecologists since the periodic cutting of areas, or coupes, allows the ground flora to recover and provides a diversity of habitat.

The nuts, also known as cobnuts, are set into distinctive husks, almost as long as itself and with toothed lobes. The name cobnut came from a game of the same name in which a nut was thrown (cob meant to throw gently) at a pile of nuts. Nuts falling from the pile belonged to the thrower.

In pre-agriculture days the nuts were a vital source of carbohydrate in northern Europe - Mesolithic man is known to have used them as a staple and the selection and breeding of cultivated forms dates from classical times. The Tudors favoured the Filbert (Corylus maxima) which came from southeastern Europe and southwestern Asia - named after St Philbert's day, 20th August, when the nuts were supposedly ripe.

Developing nuts in a distinctine husk. Leaves are alternate, toothed, shallowly lobed and downy especially on the underside. Image By Isidre blanc (Own work) (http://creativecommons.org/licenses/by-sa/4.0)

The nuts, even in the wild, were greatly valued until relatively recently. Many properties would have some trees for the sake of the nuts. Richard Mabey tells of the owner of Hatfield Forest who, in 1826, complained 'as soon as the Nuts begin to get ripe ... the idle and disorderly Men and Women of bad Character from [Bishop's] Stortford ... come in large parties to gather the Nuts or under pretence of gathering Nuts to loiter about in crowds and in the Evening take Beer and Spirits and Drink in the Forest which affords them an opportunity for all sorts of debauchery.'

But then, in the 1870s, the grey squirrel was introduced to Britain and in no time they began to decimate the harvest. Very soon the squirrel population exploded to the extent that ripe nuts are now very hard, if not impossible, to come by. The squirrels can help to disperse the seeds, but their numbers are now such that very few are thought to survive to germinate and Hazel will likely need our intervention to survive here in perpetuity. Certainly, the nuts we buy for our desserts and chocolate bars are imported now. If that's not bad enough, these blighters strip bark from trees, especially the Beech, which I regard as unforgivable - but that's another story.

Image By Rapaceone (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Without nuts to tempt you, the late winter catkins and yellow autumn colour have not sufficed to earn the Common Hazel much of a presence in our gardens and parks - but where space permits the Turkish Hazel (Corylus colurna) makes a fine pyramidal tree of up to 25m in height; in smaller gardens ornamental varieties are regularly seen - such as the twisted branches of the Contorted Hazel (Corylus avellana 'Contorta'); the pendulous form (C. avellana 'Pendula') and the Purple-leafed Filbert (Corylus maxima 'Purpurea')

Contorted of Corkscrew Hazel. Image assumed to be ByFarbenfreude (based on copyright claims). CC-BY-SA-3.0 , via Wikimedia Commons

The delicately cut leaf of C. avellana 'Heterphylla'. Image By Kenraiz (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html)

Purple Filbert image By Jerzy Opioła (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html)

A young (40 yrs) definitely more tree-like Turkish Hazel.

Sources:

Mabey, R. Flora Britannica
Bean W J. Trees & Shrubs Hardy in the British Isles
Wikicommons